Tildes: the shared Unix computers

Imagine a computer running somewhere. You connect over SSH with your key. A Unix environment appears in front of you, and pwd shows that you are in your own home directory. You type who and see other people logged into the same machine as you. You don't know who they are, but you can finger them and read their .plan. You can even run write to send them a message that will pop up in their terminal. Someone replies that there is an IRC server where everyone hangs out. You run weechat and join the conversation. They say hello. One user tells you there is more documentation on the "forum", a bulletin board, and that you can open it with bbj. You find plenty of information. Reading the threads, you discover that you have a personal website in ~/public_html, published at https://server/~user/. You quickly run nano ~/public_html/index.html and write a few lines of HTML. You check how it looks with lynx. You send an internal email with alpine to the IRC contact who helped you earlier, thanking them and inviting them to visit your new site. While you wait for an answer, you open tin, the news reader (NNTP), to catch up on the news of your small community.

This is not nostalgia for the 90s: it exists today, and it is called a tilde.

What is a tilde

A tilde is a shared, public access Unix computer. Its admin gives you an account, you log in over SSH and you get your own home directory, your shell, your website, your email and your programs. Resources are shared with the rest of the users: the CPU, the disk, the installed programs, and so on.

It is not a platform, a service or a protocol. It is a machine with Unix, an admin and a community.

Paul Ford, the creator of tilde.club, put it like this:

Tilde.club is one cheap, unmodified Unix computer on the Internet.

In practice, almost all of them share these features:

• A shell account: you log in with ssh user@server and work in the terminal as if it were your own computer.
• A personal website: whatever you save in ~/public_html is published at https://server/~user/.
• A local community: IRC chat, internal email, terminal forums and classic commands to see who is online.

They are non-profit: they run on donations and on the time of one or more volunteer admins. And this works because they are small servers, from a dozen to a few thousand users.

Why it is called a tilde

Because of the ~ symbol. On Unix, the tilde stands for your home directory. As Paul Ford said, it is a little like the @ on Twitter, a shortcut that says "here is a person".

Here is an anecdote you can tell your grandchildren. That use of the tilde comes from the Lear-Siegler ADM-3A terminal from the 1970s, where the ~ key and the Home key were the same.

The Tildeverse

The Tildeverse describes itself as "a loose association of like-minded tilde communities". There is no central authority. Each server has its own admins and rules, but they share services and interests. One tilde may only offer Gemini and Gopher, while another has IRC, Mastodon and live radio. The key is that users can move between them and meet: it is a federation of servers, not of applications.

As I write these lines, it has 13 members: aussies.space, cosmic.voyage, ctrl-c.club, envs.net, rw.rs, texto-plano.xyz, tilde.club, tilde.green, tilde.guru, tilde.institute, tilde.pink, tilde.team and tilde.town. If you like to poke around, the full list is available as JSON, with the creation date, operating system and admins of each one. There is a bit of everything: Debian, Fedora, OpenBSD, FreeBSD and even NetBSD.

On top of the servers there is a layer of shared services:

• tilde.chat: the Tildeverse IRC network (irc.tilde.chat, port 6697 with TLS), with web chat, an XMPP gateway and a Mumble server.
• tilde.zone: a Mastodon instance for tilde users.
• tilde.news: a link aggregator in the style of Hacker News.
• tilderadio.org: a radio station with live DJs. "It's radio minus radio."
• tildegit.org: a Git forge for community projects.
• Also: a terminal forum (bbj), a zine, a shared journal, a pastebin and Gopher space.

Nobody forces you to use every service, to socialize or to explore the Tildeverse. But the fun is in bumping into people from your server or from others.

House rules

Each tilde has its own code of conduct, and almost all of them fit in one line. This is tilde.club's:

No drama. Be respectful. Have fun.

tilde.town's is even shorter: "Be kind to each other". But behind the brevity there are clear rules:

• No cryptocurrency mining: on tilde.town it means an immediate and permanent ban.
• Nothing commercial: your web space is not for business or advertising.
• Don't hog resources: the machine belongs to everyone. Don't use it as a backup drive, a proxy or a backend for your IDE.
• No port scanning and no VPNs: tilde.team bans them, and it has also added a very 2026 rule: no AI agents or services on the server.

My favorite is the motto of texto-plano.xyz, the Spanish-speaking tilde: "let's be few but united". It sums up the philosophy better than any manifesto. A small community is not a limitation, it is the goal. That is why signup forms ask what interests you about the server: they want to make sure there is a curious human being on the other side.

Tildes to explore

Here is my list of active tildes, with their website, approximate number of users and some notes. It may be different tomorrow, but you can keep in mind that the most popular one is tilde.town, with almost 4,000 users.

SDF deserves a special mention. It is the grandfather of them all, with almost 40 years behind it, and it works with a different model: the basic account is free, and a one-time fee of $36 (ARPA) gives you lifetime access to more services.

Not everything is pretty

Tildes are machines with people behind them, and that comes with risks.

In May 2026, tilde.town had to close access because of a kernel vulnerability with no patch available. It opened, closed and reopened over two weeks, disabling kernel modules and replacing Nginx with Caddy.

In August it was tilde.team's turn. Someone got root access and ran rm -rf /. Daily backups limited the loss to a few hours, but they had to disable SSH and move the shared Tildeverse services to another machine.

Sharing a computer with thousands of strangers has a price:

• You depend on the admin. If they get tired, fall ill or lose interest, the server disappears. Grex closed in 2023 after 32 years, and the list of dead tildes is long.
• Root sees everything. Your files live on someone else's machine. Don't keep secrets there.
• Security is shared. A kernel bug or a compromised account affects the whole community.
• Your identity is borrowed. ~user@server is yours as long as the server exists, just like an account on a Mastodon instance.

These are risks you should know and accept before requesting your account.

Final notes

Tildes are a corner that makes the internet a nicer place: you log in, say hello, see who is around, learn new commands, edit your website and read the news. A place shared with people as curious as you.

In 2014, Paul Ford wrote that when people talk about "cloud computing" they are talking about "millions of tiny ghost towns": servers running where nobody lives. A tilde is the exact opposite: a small town that smells of coffee, with neighbors who greet and help each other.

If you end up joining a tilde, I would love to finger you. ;)

Sources

• Tilde.Club: I had a couple drinks and woke up with 1,000 nerds, Paul Ford's account (October 9, 2014) of how tilde.club was born. His quotes come from here: the cheap Unix computer, the ~ as the @ and the ghost towns of the cloud.
• tilde.club: its code of conduct, its signup form and its wiki, where the commands in the introduction come from: the command line guide (bbj, lynx, alpine, nano), the IRC page (weechat) and the tin page.
• Tildeverse, its member list and the JSON version.
• tilde.chat, tilde.zone, tilde.news, tilderadio.org and tildegit.org, the shared services of the Tildeverse.
• tilde.town: its code of conduct and its blog, with the May 2026 kernel vulnerability lockdown.
• tilde.team, with the notice about the August 2026 attack and its terms of service.
• texto-plano.xyz and its code of conduct.
• SDF Public Access Unix System on Wikipedia, for its history, and the SDF join page, for current prices.
• The Grex shutdown notice from 2023 and its history.
• Tilde on Wikipedia, on the origin of ~ as the home directory and the ADM-3A terminal.
• I checked the user counts and the status of each tilde by visiting their websites and user lists on October 19, 2026.